In the field of multilamp photoflash arrays, it is necessary to effect electrical connection of a plurality of flashlamp electrical conductors to a printed circuit affixed to a circuit board. Among the techniques employed to effect such electrical connections are twisting, soldering, welding, ultrasonic bonding and by means of fasteners such as screws, eyelets, clamps and rivets for example.
More specifically, U.S. Pat. No. 4,048,716 of Jehlicka suggests a photoflash array wherein a plurality of eyelets are affixed to a circuit board in electrical connection with a printed circuit. The electrical leads of the flashlamps are inserted into the eyelets and the extended shank portion of the eyelets is bent to capture the electrical lead within the eyelet and the eyelet in the circuit board.
Another known approach to affixing the leads of flashlamps to a printed circuit of a multilamp photoflash array is suggested in U.S. Pat. No. 4,028,798 of Bechard et al. Herein, electrical connection between the electrical conductors of the flashlamps and a printed circuit is effected by a method wherein a tool drives the flashlamp conductor through a plastic member, such as a circuit board, and into contact with a printed circuit run. The tool may be heated or vibrated such that the flashlamp conductors are held in place by embedment in the circuit board material. Other alternatives suggested include a method wherein the flashlamp conductors overlap the printed circuit and are driven into the circuit board adjacent the printed circuit run. Also, the flashlamp conductors may be inserted into openings in the circuit board and driven into contact with the bottom side of the printed circuit run by embedment into the circuit board with a heated tool.
Another somewhat related arrangement is suggested in U.S. Pat. No. 4,334,262 issued to Latos. Therein a multilamp photoflash array includes a plurality of flashlamp, each having a pair of electrical conductors. These electrical conductors are affixed to a printed circuit, by soldering for example, secured in slotted openings. The conductors are bent back upon themselves to provide a spring action whereby the mechanical spring action supports the flashlamp intermediate the front and back covers of the array.
Although the above-described methods and photoflash arrays utilizing the various-described techniques for attaching flashlamps have been and still are utilized with varying degrees of success, there are structures and photoflash arrays which have different requirements. For example, photoflash arrays of the miniaturized variety wherein space is severely restricted encounter considerable difficulty in attempting to employ eyelets which are not only expensive but also require much needed space. Also, structures which employ thermoplastic materials are severely limited in so far as the use of soldering because of the limited temperature tolerance of the thermoplastics.
Various techniques for affixing the flashlamp leads and establishing electrical connection thereof to a printed circuit without welding, soldering or eyelets are suggested in patent applications bearing U.S. Ser. Nos. 359,465; 359,468; and 359,467, all filed Mar. 12, 1982. Therein, the electrical leads of the photoflash lamp are trapped intermediate a plastic reflector and a printed circuit. However, in each instance, the printed circuit and the reflector unit must be either perfectly flat or have an interference fit in order to establish reliable electrical contact. However, an interference fit tends to cause undesired problems because the electrical leads hold the circuit board and the reflector member apart which not only causes misalignment but also is deleterious to sonic sealing since the sonic energy tends to undesirably embed the electrical leads in the plastic reflector.